64 the FORMATION OF PROTEIDS IN PLANT-CELLS. 
be any other one than form-aldehyde. If the fungi utilise once 
leucin, another time tyrosin, a third time tartrate of ammonia, 
then an oxidation must set in to reach the common starting 
point. I} And this must hold good also for the higher plants, for 
it can hardly be assumed that the mode of protein formation is 
here entirely different. If for the purposes of transportation and 
transformation (conglutin into active albumin and living pro¬ 
toplasm), in lupin-shoots, the reserve protein is first dissolved, 
and split into a series of amido-products (leucin, admido-valeri- 
anic acid, tyrosin, phenyl amido-propionic acid, arginin, etc.) by 
an enzyme, then in all probability and logically all those different 
products must be transformed into the common starting group : 
formic aldehyde, and their nitrogen be liberated as ammonia; 
thus the decomposition of leucin by oxidation might be expressed 
by the following equation : 
C 6 H I3 N 0 2 + 70 = 2 C 0 2 + H 2 0 -{- 4 CH 2 0 -l-NH 3 . 
Form-aldehyde and ammonia, however, act noxiously and do 
not remain as such for a second ; aspartic aldehyde being formed. 
This product however does neither remain unchanged, it will yield 
either directly active albumen when all conditions are fulfilled, or 
it will be stored up as asparagin if not all conditions are united 
for protein production. 1 2 3) 
The asparagin in plants has two sources; it may either be 
formed directly from glucose, ammonia (or nitrates) and sulfates, 
or it may be a transitory product between protein-decomposition 
and reconstruction from the fragments. In both cases the im¬ 
mediate processes connected with the formation of asparagin have 
the greatest resemblance or are even identical,—although the 
original materials are far different. 
1) Compare Chapt. Ill and Chapt. VIII of this essay. I developed the outlines 
of this hypothesis first in Püflg. Arch. 1880. 
2) The still hypothetical formation of aspartic aldehyde, from formic aldehyde 
and ammonia may be expressed by 4CH20 + NH3 = C 4 H7N02 + 2H20 
3) Closely related to asparagin is succinic acid, found not only often in the 
higher plants, but also encountered in fungi. I found this acid also in algae 
(Spirogyra), in hay of meadows, in the cambial sap of conifers and in the common 
yeast (Ber. Bayr. Akad. d. Wiss. 1878 ; Journ. f. prakt. Chem. 36). I observed 
also this acid as a product of oxidation of albumen by potassium permanganate 
(Journ. prakt. Chem. 31, 152). 
